Evaporating apparatus



(No Model.)

A. A. BENTON. EVAPORATING APPARATUS.

No. 339,889. Patented Apr. 6, 1886.

INVE/VTUR fllbert JZ Z7671 ion Fig.3.

j fy

W/T/VESSE-S n. PETERS. fimwlitfwgnphur, warring. ac.

rrn dra ns PATENT Denice.

ALBERT A. BENTON, OF BAVARIA, KANSAS.

EVAPORATING APPARATUS.

EiPECIFICATIQN forming part of Letters Patent No 339.359, dated April 6, 1886.

Application filed May 23, 1835. Serial "30.1%,469. (No model.)

rating many kinds of liquids by air. The shorter the time of exposure to even moderate heat the better is the product. The time necessary for evaporation may be lessened by diminishing the quantity of liquid operated on at one time, other things being equal. For instance, it requires one-fourth of the time to evaporate twcntyfive gallons of water, which is necessary to evaporate one hundred gallons of water. In the former case less injury is occasioned to the substances in solution than in the latter case. It is thus advisable to operate on smaller quantities of liquid at a time,

To all whmn it may concern:

Be it known that l, ALBERT A. DENTON, a citizen of the United States, residing at Bavaria, in the county of Saline and State of Kansas, have invented certain new and useful Improvements in Apparatus for Evaporating Liquids by Air, of which the following is a specification, reference being had therein to the accompanying drawings. 1

Figure 1 is a side elevation of a device embodying the present invention, the case or covering being removed; Fig. 2, aside elevation, showing the elevating devices being inclined; Fig. 3, sections showing slats fixed and thus lessen the time of exposure to heat, to a wheel; Fig. 4:, asection showing the elewhich is necessary for evaporation in all possible ways.

The basin A in the apparatus previously described necessarily containsa comparatively large quantity of liquid in order to completely immerse the slats when they pass through the basin, and thus to uniformly wet all the surfaces. It is also difficult or impossible in some cases to allow the liquid to enter the basin A continuously and to draw 0d the liquid from the basin A continuously, preserving the proper level of liquid in the basin A, and consequently the liquid is frequently admitted into the basin A in considerable quantities at a time, and is drawn out at intervals, as desired. This necessitates still greater capacity in the basin A, in order that theliquid,when reduced by evaporation, may still completely cover the slats of the liquid conveyer as they pass through the basin A, and thus uniformly Wet all the surfaces of the slats. It is also advisable to reduce the quantity of liquid necessary to operate on at a time for other reasons. For instance, if fifty gallons of liquid is necessary to completely immerse the slats as they pass through the basin, it requires fifty gallons of liquid to begin operations with the apparatus, and at the close fifty gallons of imperfectly-finished liquid remain in the basin, or else the slats are imperfectly wet at the beginning and the ending of the operation. \Vhen the slats are imperfectly wet the liquid is sometimes overdried and adheres to the slats in masses, and the product is inferior.

In cases where it is desired to evaporate liquids of great density and viscidity as, for instance, molasses--using cold air in winter, the

vating devices operating on a curve. Fig. 5 shows modification of the sizes of the elevatorwheels; Fig. 6, detail to show how slats are l fixed to the arms of the spokes of the hub, Fig. 7 showing cowl attached to the chamber 13.

The object of this invention is to improve an apparatus for evaporating liquids by air, which was patented to me December 23, 1884., No. 309,775; and also an apparatus for exposing large surfaces of liquid to air or vapor or gas, my application for which is now pcnding,-and also an improvement on both of the preceding apparatus, for which my application for a patent is now pending.

The improvement consists in using an improved method of wetting the slats oi the liqnidconveyers D D in the above-mentioned apparatus.

It also consists in an of the liquidconveyers in apparatus.

It also consists in using means to improve 1 the draft of air through the apparatus.

It is well known that long exposure to heat, as in boiling, injures and degrades many liquidsas, for instance, saccharine liquids. It is also well known thatlong exposure to a more moderate degree of heat-as, for instance, long improvedconstruction l theabove-inentioned l continued boiling in a vacuuurpan-also 1njures and degrades many liquids. For instance, if a solution of sugar is boiled for three hours at a temperature of 220 to 235 Fahr- If it is boiled for it is also The same is true in evapoenheit, it is greatly injured.

thirty-six hours in a vacuum-pan, greatly injured.

slats then move through the liquid in the basin A with difficulty, and it is then necessary to make them excessively strong and heavy, and it requires, more power to give motion to the liquid-conveyer D. For these and other rea sons it is advisable to improve the method of wetting the slats ofthe liquid-conveyor D. I accomplish these objects by pouring or spray ing or showering the liquid upon the moving evaporating-surfaces of theli quid couveyer D, instead of causing the slats of the liquid-conveyer to pass through and be immersed in the liquid in the basin A.

In cases where the liquid is thin and fluid the liquid may be elevated by the liquid-elevatorc, Fig. 1, and may be sprayed through an atomizer or a perforated nozzle, (Z, Fig. 1, upon the moving surfaces of the liquid-conveyer D as they pass the atomizer or perforated nozzle (Z. The liquid which flows off from the slats, or the excess of liquid which is necessary to completely wet the moving slats, flows down into the basin A, which returns it to the reservoir b, when it is again elevated and sprayed upon the moving slats, and thus evaporated until it has sutficientdensity. The atomizer or nozzled, Fig. 1, may be placed in any position with reference to the liquid-conveyer D suitable to most completely wetting the slats. In some cases it is elevate the liquid into a basin, a, from theres ervoir b, Fig. 2, the basin a having a perforated bottom or perforated side, thus sprinkling the liquid upon the movingevaporatin surt'aces of the liquid-conveyer D. The basin a may be placed at the top of the liquid-con veyer D, or in any suitable position with reference to the liquid-conveyer D, so as to wet the moving evaporating-Snrtaces of the liquid-conveyer D, the most completely, accord ing to the construction of the liquid-conveyor and the nature of the liquid, and the excess of liquid necessary to completely wet the moving cvaporating-surfaces of the liquid-conveyer D is received by the basin A, which returns it to the reservoir 1), where it is again elevated until the liquid is sufficiently condensed. In some cases, particularly in dense and viscid liquids, it is better to use continuous openings or slots, which may be wholly or partly closed or regulated by slides or equivalent in the basin a, as shown at c c, Fig. 3, so that the liquid may be poured upon the moving evaporating-surfaces of the liquidconveyer D in sufficient quantity to completely wet them, and when desired, two or more of these continuous openings or slots may be used, as shown at e c, Fig. 3. By this means the openings or slots may be widened, to increase the flow of dense viscid liquids, and narrowed when thin fluid liquids are operated on,to suit the varying degrees of density. The excess of liquid necessary to completely wet the moving evaporating-surfaces of the liquid conveyer D is received by the basin A,which returns it to the reservoir, where it is again elevated to the basin a,until sufficiently condensed. By these means the quantity of liquid necessary to operate the apparatus at a time is greatly lessened, being only the quantity necessary to completely Wet the moving evaporating-surfaces of the liquidconveyer D and a sufficient excess to insure wetting the slats. I also deem it better to have the reservoir divided into two compartments, 6 b, Fig. 1, so that while the small quantity of liquid in one of the reservoirs, b, is being evaporated, the other reservoir, b, which has already been evaporated, may be emptied and refilled with the liquid which is being evaporated, so that the process of wetting the slats may be continuous without intermission, to avoid overdrying the liquid on the moving slats, which in some cases injures the product. This method ofwetting the slats makes certain changes in the the liquid-conveyers D necessary or possible. Thus it was not practicable to use a simple rotary wheel or cylinder closely set with slate or strips of metal orof wood, the slats bein wet by passing through the liquid in thelarge basin,which was necessary in this form of apparatus, and these slats affording the evaporating-surfaces when in contact with the air above the basin,because the quantity of liquid necessary to immerse the lower slats was too large in comparison with the evaporating-surfaces of the upper slats.

It will be readily seen by inspecting Fig. 3 that it would require a large quantity of liquid to completely immerse the lower slats of the cylinder f, and only an equal surface of the upper slats would be efficient as evaporatingsurface, while the evaporating-surface should be as large as possible, and the quantity of liquid operated on as small as possible; but by the above-described method of wetting the slats the quantity of liquid necessary to completely wet the moving evaporatingsurfaces is largely reduced and the rotary wheel orcylinderf, Fig. 3, is simpler, cheaper, more compact, durable, and stronger than the otherwise necessary oblong liquid-conveyers previously described.

In constructing a rotary wheel or cylinder for evaporating purposes, I prefer to use a hub or axis, F, having spokesf, to which the slats may be fastened by any suitable method of attach ment nearly parallel to each other aproper distance apart,to allow both air and also liquid to pass between them, and having snfficient surface in the combined slat-s to give the required evaporating capacity of the apparatus. Itii evident the slats may be attached to the whe ll, Fig. 3, in such a position that the air may pass between them parallel with'the axis ofthe wheel or cylinder, or they may be placed in such a position that the air of metal or of wood, 9, Fig. 3, along or around the circumference of the wheel or the cylinder f, Fig. 3, parallel with each other a proper distanceapartto allow both air and the liquid to circulate or pass through then1,and also to place other strips, h, below the outer series of slats. also a proper distance apart to allow air and liquid to pass between and through them, and this second series of slats placed so that each slat is under the space between two of the first series of slats, g, as shown in Fig. 3, and another series of slats, 2', also similarly spaced below the second series, and so on until the wheel or cylinder f, Fig. 3, is filled with slats and the necessary evaporatirig-surface is obtained. The first series of slats, 9, Fig. 3, is spaced differ ently or staggered with referencetothe sec ond series of slats, h, and the second series of slats, h, is also spaced differently or staggered with reference to the third series of slats. '1", and so on, in order that the descending liquid may not uselessly pass through the spaces between the slats without cominginto immediate contact with any of the slats before it reaches the basin A. The excess of liquid passing through the slats g in the first series of slats thus comes in cont-act with the slats h of the second series of slats, and so on until the final excess reaches the basin A, which returns it to the reservoir 2), where it is again elevated and poured upon the moving slats until it is sufficiently condensed.

To be more specific in describing the construction of the wheel or cyliuderf, Fig. 3, 1 use an axis or hub, F, of suitable length-say, for instance, fourfeetthe axis carrying arms or spokes, to which the strips may be fastened. On the outer circumference of the spokes or arms I rigidly attach a series of slats or strips, gsay four feet long and six inches wide-placed parallel to each other around the circumference, say, one inch apart, and the series firmly fastened to each other and to the spokes by bands, or in any suitable way.

Below this first series I place asecond series of slat-s, h, similarly spaced and similarly fastened to each olher'and to the spokes, and spaced with reference to the first series, so that each slat of the second series comes in contact with the liquid which passes through the spaces of the first series, and so on until the cylinder is complete. I inclose the cylinder with a casing or airchamber, B. Liquid is placed in the reservoir 2) and is elevated by the liquid-elevator c, Fig. 3, to the basin a, and descends through slots or openings in the basin a, the flow through the slots or openings being regulated by the slides e c, Fig. 3, or other device upon the slats g h i. Motion is given to the cylinderf by a driving-pulley, Z, on the axis of the cylinder B, so that all of the slats come in contact with the liquid descending from the basin a. A current of air at the proper temperature, according to the nature of the liquid and according to the work to be done, passes through the slats of the cylinder f in a direction parallel with the slats, and this air, coming in contact with the wet surfaces of the slats, absorbs and removes the wal conveyer and air-chamber in Fig. 2.

ter from the liquid being evaporated. The excess of liquid passing through the slats to the basin A returns to the reservoir 1) by suitable connection, and is again elevated to the basin a until sufficiently condensed. When the liquid in the reservoir b is evaporated it is removed, and the reservoir 1) is then evaporated, while the first reservoir is being emptied and refilled.

The oblong liquid conveyers described in my patent dated December 23, 1884, and also in my subsequent applications now pending, may also be modified to adapt them to this method of wetting the slats. Theliquid-conveyer D and the air-chamber may be inclined, and the liquid may be elevated from the basin A by the elevator G, Fig. 2, and may be poured or sprayed upon the moving slats near the bottom of the liquid-conveyer D, Fig. 2. The liquid may be elevated from the basin A and sprayed between the ascending and the descending sides of the vertical conveyor D, as shown in Fig. 1. The liquid may be elevated to a basin, (1, at the top of a vertical liquid-conveyer and pass through the perforations upon the moving slats. It may also be poured from a basin having continuous openings or slots, the width of which openings may be regulated so as to regulate the flow of liquid, as shown in Fig. 3. This form is preferable in some cases-for instance, where the substances in solution crystallize or grain while being evaporated, as they frequently do when suiiiciently condensed, and the crystals close narrow openings or perforations, and also in the case of gummy and viscid liquids.

By using guide-wheels m, Fig. 4., the liquidconveyer I) and the air-chamber B may be verti al while the foot or bottom of the liquidconveyer is inclined, so as more conveniently to wet the slats at the bottom of the liquidconveyer, as was done wit-h the inclined liquid- It is advisable to have the liquid elevator G. Figs. 1, 2, 3, which elevates the liquid, of sufiiciently large capacity in order that theliquid may be ample in quantity to insure completely wetting the slats.

In order to require less constant attention, I construct the basin a, Fig. 3, with an outlet below the upper edge of thebasin. This outlet carries any excess of liquid upon the moving slats and avoiding an overliow of the basin a. I also place the outletj of the basin A, Fig. 1, which returns the excess of liquid to the reservoir b, above the bottom of the basin A, in order that it may always contain some liquid, so that the air in the hot-air chamber 0, under the basin A, may warm the liquid as it passes through the basin A, as is more fully described in my previous application now pending.

In my last application, now pending, in the construction of an oblong liquid-conveyor, I described admitting the hot air to a central vacant space between the ascending and the descending sides of the liquid-conveyer D. I deema central vacant space important for the following additional reasons, and as I did not fully describe and claim the central vacant space, I wish now to do so. I find upon trial that when the compound slats are composed of single slats compactly placed together, leaving small spaces between them, and when the compound slats are closely placed together upon the chains or belts, leaving small spaces between them, and when the liquid-conveyer is of considerable height, as it should be, in order to have large evaporating-surface, then the hot air becomes saturated before it reaches the top of the air-chamber, and consequently the upper part of the air-chamber is useless as evaporatingspace. I avoid this by leaving a sufficiently large central vacent space, 1), Fig. 5,which is a sort of air-chamber. This allows a much larger quantity of air to pass through the air-chamber than when there is no central vacant space or small central space. It also renders the air more uniform in regard to saturation in all parts of the air-chamber B, and thus allows the liquid-conveyor to have more height and to contain more compound slats. I prevent air passing directly up through the central space, 1), by using deflectors g. These are better placed near the upper part of the air-chamber, to allow air to pass partly through the air-chamber before coming in contact with the wet surfaces of the slats. By using larger wheels, G, Fig. 5, at the top of air-chamber B and smaller wheels, G", at the bottom of the air-chamber, and still smaller wheels, G in the basin A, I am able to leave as large a central air-space as is desired, and to have the dropping liquid wet the sides of the airchamber B, as previously described, and also to have the basin A as small asis possible with agiven size ofliquid-conveye1z In cases where the air-chamber B passes through the roof of the building containing the apparatus the wind sometimes interferes with the currents of air passing through the apparatus. To avoid this, I affiX ahood or cowl, r, Fig. 7, to the cover of the air-chamber B, which may be of any suitable construction. It is evident air-spaces can also be used on the side walls of the air-chamber B, and similar deflectors as well as a central air-space, thus largely increasing the quantity of dry air in the apparatus.

What I claim, and desire to secure by Letters Patent, is

1. In an evaporating apparatus, a system of moving slats or liquid-conveyers, combined with spraying orwetting devices whereby the moving surfaces of said slats or conveyers are moistened or wet by sprinkling, spraying, or pouring the liquid thereon, substantially as described.

2. In combination with a system of moving slats or liquid conveyers and a spraying or wetting device, means for forcing the liquid from the reservoir to and through the said spraying or wetting device, substantially as described.

3. A rotary cylinder liquid-conveyer with or without a casing or air-chamber, as set forth.

4. In combination with a system of liquidconveyers, a spraying or wetting device and means for forcing the liquid through said device, a reservoir divided into two parts whereby one can he used as the other is filled, substantially as described.

5. The liquid-elevator c, the perforated basin a, or the slotted basin a, with the regulating-slides e e, or substantial equivalent, and the atomizeror nozzle (1, as set forth.

6. In an evaporating device, an inclined air-chamber combined with inclined moving liquid-conveyers, substantially as described.

7. In combination with ascending and de scending liquid conveyers, a spraying or sprinkling device located within or between said ascending and descending conveyers, sub stantially as described.

8. Spraying or pouring the liquid between the ascending and the descendin sides of the liquid-conveyor, as set forth.

9. The guide-wheelsm, Fig. 4, in a vertical liquid-conveyer, having an inclined part or portion, as set forth.

10. The overflow-pipe n of the basin A, and the overflow pipe or outlet, Fig. l, as set forth.

11. In an evaporating apparatus, as described, the provision of larger wheels to support the liquid -conveycr at the top and smaller Wheels at the bottom of theair-chamher, and still smaller wheels to support the liquid-conveyer in the basin, thus reducing as far as possible the size of the basin and allowinga central air-space, and also wetting the sides of the air-chamber, as set forth.

12. The hood or cowl r, as set forth.

13. In an evaporating apparatus, as described, the provision of sides paces or airspaces on the walls of the air-chamber, as also a central airspace, thus largely increasing the quantity of dry air in the air-chamber, as set forth.

14. Placing deflectors in the air-spaces on the sides of the air-chamber near the upper part of the spaces, thus furnishing dry air to the upper slats of the liquid-conveyer, and also in a central air-space, as set forth.

15. In an evaporating apparatus, revolving liquid -conveyers arranged staggering, each slat separated from its contiguous slats and combined with a spraying device, substantially as shown and described.

In testimony whereofI aflix my signature in presence of two witnesses.

ALBERT A. DENTON. Witnesses: G. F. GREEN,

QRLO HUBBARD.

IIO 

